Differential pulley.



Patentd luly 3|, I900.

0. .E. SGBIMGEOUR DIFFERENTIAL PULLEY.

(Application filed Oct. 7, 1899.)

Y 3 Shoots-Sheet I.

(No Model.)

No. 654,68l.

C. E. SCRIMGEOUR.

Patented luly 3|, I900.

3 Sheets-Sheet 2.

INVENTOR JMQW ATTORNEYb No. 654,6 8l. Patented July 3|, I900.

c. E. scmmeaoun.

DIFFERENTIAL PULLEY,

(Applicatiqn filed. Oct. '7, 1899.) v (l'lo Model.) V 3'Shaets-Shent 3,

WITNESSES: i INVENTOR UNITED STATES 1 P TENT OFFICE.

onARLEs soRnneEoUR, or. LEWISTON, MAINE, ASSIGNOR on ONE-HALF TO WILBERFORCE B. HAMMOND, or CAMBRIDGE, MASSACHUSETTS.

oiFFE ENT-rAL PULLEY.

SPECIFICATION formingart of Letters fatent No. 654,681, dated July 31,1900.

Application filed dctober'h 1899- To all whom it may concern: I ,7

Be it known that I, CHARLES E. ScRi GEOUR, a citizen of the United States, and a resident of Lewiston, in the county of Androscoggin and State of'Maine, have invented certain new and useful Improvements in Differential Pulleys, of which the following is a specification.

The object of my invention is to provide a differential pulley of such character that by simply shiftinga belt laterally from one portion of it to another the speed transmitted may be varied within very wide limits.

In the accompanying drawings, Figure 1 represents my improved pulley combined with a belt, belt-shifter, and driving-drum. Fig. 2 represents a vertical longitudinal-section of the pulley. Fig. 31's an end view of one section of the pulley with a diagram of the three gears adjacent thereto. Fig. 4 is a detail of the belt-shifter.

1 is a belt leading from the driving-drum 2 on the counter-shaft 3 about the differential pulley to drive it.

4 is a shaft held from rotation in anysuitable standard, as 5, and having keyed to it at intervals a series of gears I) 19 17 Rotatably mounted upon said shaft t are the pulley-sections or a a a a c c c are internal gear-teethon the pulley-sections a, a and airespectively. The gears d and e, rotatably mounted upon the studs f g, fixed parallel with the shaft 4 on the pulley-section a mesh with the gears b c. The gears d and c rotatably mounted upon the studs f g fixed parallel with the shaft 4 to the pulley-section (1 mesh with the gears 0 D The gears 61 and c rotata bly mounted upon the studs f 9 fixed parallel with the shaft 4 to the pulley-section a, mesh with the gearsc 11 The hub 25 of pulley-section 0, extends beyond the end of the shaft at over the end of the driven shaft 6, to which the hub 25 is fixed by a set-screw 7 or other suitable means. The shaft 6 runs in suitable hearings on standards 8 and 9 and drives a pulley 10. The pulley-sections a a (t a a beingequal in diameter and placed sent-1m. 732,895. (No model.)

contiguous with each other in axialalinement, form a practically-continuous cylin 5o drical surface, parallel with which is placed the bar 11, which is supported upon arms 12 and upon which is supported the belt-shifter l2 andits carriage. The barll passes through the frame 13 ofthis carriage, and upon said frame is mounted a stepping-wheel 14, moved by the hand-wheel 15. 16 represents notches in the bar 11, spaced to correspond with the points of the stepping wheel 14, so that by turning the hand-wheel 15 one-quarter of a revolution the stepping-wheel 1 1 will move the carriage, and with it the belt-shifter, the distance between two notches. This distance is also made to correspond with the width of the pulley-sections, so that for each one-quarter revolution of the hand-wheel 15 the belt 1 is shifted from one pulley-section to thenext. The operation is as follows: The belt 1 is driven at a constant speed by the pulley 2 and when upon the pulley-section crturns this pulley-section and nothing more, because that pulley-section is loose upon the shaft 4 and is not geared to the adjacent pulley-section a. If now the attendant without stopping the belt 1 turns the hand-wheel 15 onequarter revolution, he shifts the belt 1 from the pulley-section a to the pulley-section a, which is immediately driven by the belt, and through its internal gear 0 compels the gears d and e to travel around the stationary gear 11 and carry with them their journalpins f and g, and consequently the pulleysection a which in turn by a similar mode of operation drives the pulley section a which in turn by a similar mode of operation drives the pulley-section a, which drives the shaft 6. If the arrow 26 represents the direction in which the pulley-section d, is driven, the arrows 17 and 18 wilhrepreSent the direction in which the gears (1 and 6', respectively, are driven, and the arrow 26 will represent the direction in which the journalpins f and g, and consequently the pulleysections a a and a are carried. Thus it will be seen that all of the sections of the pul- 9 5 ley move in the same direction, which is es sential for cooperating with the same belt 1 and permitting such belt to be shifted from one pulley-section to another throughout the series without stopping the rotation. -The speed, however, at which each pulley-section is driven will be less than the speed of the pulley-section preceding it in the series, so that when the belt is running on the pulleysection a there will be the maximum reduction in the speed communicated to the shaft 6. This speed reduction will be less as the belt 1 is shifted onto the succeeding mem bers a a a of the pulley-section series.

When the belt reaches the pulley-section d it will drive the shaft 6 without reduction of speed. When the belt is shifted onto the pulley-section a, the speed of the pulley-sections a a and a will be accelerated, so that it is obvious that the same mode of operation may be employed for either retarding or accelerating the speed. I

I claim- A pulley containing, in combination, a series of pulley-sections a, a &c.', the peripheries of which form a' substantially-continuous cylinder; a series of internal gears c, 0 &c., carried by said pulley-sections; a shaft upon which said pulley-sections revolve; a series of fixed gears 17, b &c.; a series of planetary moving gears d, (1 -&c.', meshing with said internal gears and fixed gears, and a series of studs whereon said planetary moving gears rotate; the stud carrying'the planetary moving gear which meshes with each pulley-section being fixed to the next pulley-section of the series; substantially as described.-

CHARLES E. SCRIMGEOUR.

Witnesses: JEAN BRUYERE, A, L. HUBBARD. 5 

